As cell phones with cameras have become popular in recent years, chances photographing or imaging various objects to be photographed by using the cell phone have increased. For example, there is a case that an object such as a friend or landscape which is apart from a lens of a camera to some extent is photographed (normal photographing) and, alternatively, there is a case that an object such as a timetable for bus or petals of a flower at a position near the lens of the camera is photographed (close-up photographing).
In the close-up photographing (macro-photographing), a lens position of a camera is required to locate at a slightly nearer position on an object side than a lens position at the time of normal photographing. Therefore, this type of photographing lens system is provided with a drive mechanism for driving a lens to move in the optical axis direction. The drive mechanism is driven by changing a state of a switch to move a lens in the optical axis direction (see, for example, Patent Reference 1).
A lens drive device which is disclosed in Patent Reference 1 includes a movable lens body, a drive mechanism for moving the movable lens body in an optical axis direction, a fixed body (yoke) which movably supports the movable lens body in the optical axis direction, and a restriction means (flat spring) which restricts movement of the movable lens body. Further, the drive mechanism includes a magnet and a coil. In the structure as described above, while an electric current is supplied to the coil to generate an electromagnetic force, a restriction force against the electromagnetic force is generated by the restriction means and magnitudes of both the restriction force and the electromagnetic force are adjusted to stop the movable lens body at a desired position.    [Patent Reference 1] Japanese Patent Laid-Open No. 2007-94364
However, when the yoke and the flat spring are to be assembled, the yoke and the flat spring are required to be positioned in the optical axis direction and the radial direction. Specifically, for example, a jig which is structured so that a circular cylinder having substantially the same diameter as a lens-barrel (or lens) is stood on a pedestal is used for assembling. For example, a cover, a yoke, flat springs, a magnet and the like are required to fix in order by using the jig while positioning in the optical axis direction and the radial direction. In this manner, in the manufacturing steps for the lens drive device, positioning work is required many times due to influence of component accuracy and assembling accuracy of adhesion, fixing by welding and the like and thus working efficiency is not satisfactory. Especially, since the yoke which determines the outer shape dimension is conventionally formed by a bending work, its dimensional tolerance is difficult to make smaller and thus rattling is easily occurred in the radial direction. In order to prevent this problem, it is required that, at the time of assembling, fixing is performed while positioning in the radial direction is performed.
In view of the problem described above, at least an embodiment of the present invention provides a lens drive device which is capable of reducing the number of times of a positioning work and is capable of improving working efficiency.